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Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
The cold war
Inter-war germany
Medieval period: 1066 -1509
2d religious conflict and the church in england, c1529-c1570
2o democracy and nazism: germany, 1918-1945
1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
2m wars and welfare: britain in transition, 1906-1957
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2n revolution and dictatorship: russia, 1917-1953
2s the making of modern britain, 1951-2007
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Chemistry
9 Dec 2025
33
6 pages
Charlotte @charlotte26
Ever wondered why metals conduct electricity but plastics don't? It's all down to the type of chemical bonding... Show more
Think of ions as atoms that have either lost or gained electrons, giving them an electric charge. When a metal atom loses electrons, it becomes a cation (positively charged), whilst non-metals gain electrons to become anions (negatively charged).
Ionic bonding happens when these oppositely charged ions attract each other - it's like magnetic attraction but with electrons. You'll typically see this in compounds made from metals and non-metals, where the metal transfers electrons to the non-metal so both can achieve a full outer shell.
Quick tip Group 1 and 2 metals love losing electrons, whilst Group 6 and 7 non-metals are keen to gain them. Group 0 elements don't bother with ionic bonding because they already have full outer shells!
Covalent bonds form when atoms share electrons rather than transferring them completely. You'll find these in most non-metal compounds, and they can be single, double, or triple bonds depending on how many electron pairs are shared.
The shared electrons are attracted to both atomic nuclei, making covalent bonds surprisingly strong. These bonds create everything from tiny molecules like water to massive structures like diamond.
Metallic bonding is quite different - imagine a sea of electrons floating around positively charged metal ions. These delocalised electrons aren't tied to any particular atom and can move freely around the metal structure, which explains why metals conduct electricity so well.
Remember Covalent = sharing electrons, Metallic = sea of free electrons, Ionic = transferring electrons completely.
Ionic compounds have some pretty distinctive characteristics that make them easy to spot. They typically have high melting and boiling points because those electrostatic forces between ions need loads of energy to break apart.
Here's something interesting ionic compounds only conduct electricity when molten or dissolved in water. When solid, the ions are locked in place, but heating or dissolving frees them up to carry electrical charge.
The ions arrange themselves in a regular, closely packed pattern called an ionic lattice. This organised structure gives ionic compounds their characteristic properties and often makes them form crystals.
Exam tip Remember that solid ionic compounds don't conduct electricity - the ions need to be free to move!
Giant covalent structures like diamond and graphite are absolutely massive networks of covalently bonded atoms. Most don't conduct electricity because there are no free charged particles floating about (graphite's the exception here).
Let's look at carbon's different forms Diamond has four bonds per carbon atom, making it incredibly hard. Graphite only has three bonds per atom, arranged in slippery layers with delocalised electrons that conduct electricity. Graphene is basically one layer of graphite - super strong and great for electronics.
Small covalent molecules behave quite differently. They're usually gases or liquids at room temperature because the forces between molecules are weak, even though the bonds within each molecule are strong.
Key point Don't confuse bonds within molecules (strong) with forces between molecules (usually weak)!
Metals are brilliant conductors of heat and electricity thanks to those free-moving delocalised electrons. They also have high melting points and stay solid at room temperature because of strong electrostatic attractions.
Most pure metals are malleable (you can hammer them into shapes) because the layers of atoms can slide over each other. Alloys are different though - mixing different sized atoms distorts the layers, making them much harder.
Fullerenes are fascinating carbon molecules that form hollow spheres or tubes. These structures, made from hexagonal rings of carbon atoms, are used in everything from electronics to drug delivery systems because of their unique properties.
Cool fact Fullerenes can trap other molecules inside their hollow structure, making them perfect for targeted drug delivery!
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Charlotte
@charlotte26
Ever wondered why metals conduct electricity but plastics don't? It's all down to the type of chemical bonding holding the atoms together. Understanding ionic, covalent, and metallic bonds will help you predict how different materials behave in everyday life.
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Think of ions as atoms that have either lost or gained electrons, giving them an electric charge. When a metal atom loses electrons, it becomes a cation (positively charged), whilst non-metals gain electrons to become anions (negatively charged).
Ionic bonding happens when these oppositely charged ions attract each other - it's like magnetic attraction but with electrons. You'll typically see this in compounds made from metals and non-metals, where the metal transfers electrons to the non-metal so both can achieve a full outer shell.
Quick tip: Group 1 and 2 metals love losing electrons, whilst Group 6 and 7 non-metals are keen to gain them. Group 0 elements don't bother with ionic bonding because they already have full outer shells!
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Improve your grades
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Covalent bonds form when atoms share electrons rather than transferring them completely. You'll find these in most non-metal compounds, and they can be single, double, or triple bonds depending on how many electron pairs are shared.
The shared electrons are attracted to both atomic nuclei, making covalent bonds surprisingly strong. These bonds create everything from tiny molecules like water to massive structures like diamond.
Metallic bonding is quite different - imagine a sea of electrons floating around positively charged metal ions. These delocalised electrons aren't tied to any particular atom and can move freely around the metal structure, which explains why metals conduct electricity so well.
Remember: Covalent = sharing electrons, Metallic = sea of free electrons, Ionic = transferring electrons completely.
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Ionic compounds have some pretty distinctive characteristics that make them easy to spot. They typically have high melting and boiling points because those electrostatic forces between ions need loads of energy to break apart.
Here's something interesting: ionic compounds only conduct electricity when molten or dissolved in water. When solid, the ions are locked in place, but heating or dissolving frees them up to carry electrical charge.
The ions arrange themselves in a regular, closely packed pattern called an ionic lattice. This organised structure gives ionic compounds their characteristic properties and often makes them form crystals.
Exam tip: Remember that solid ionic compounds don't conduct electricity - the ions need to be free to move!
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Improve your grades
Join milions of students
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Giant covalent structures like diamond and graphite are absolutely massive networks of covalently bonded atoms. Most don't conduct electricity because there are no free charged particles floating about (graphite's the exception here).
Let's look at carbon's different forms: Diamond has four bonds per carbon atom, making it incredibly hard. Graphite only has three bonds per atom, arranged in slippery layers with delocalised electrons that conduct electricity. Graphene is basically one layer of graphite - super strong and great for electronics.
Small covalent molecules behave quite differently. They're usually gases or liquids at room temperature because the forces between molecules are weak, even though the bonds within each molecule are strong.
Key point: Don't confuse bonds within molecules (strong) with forces between molecules (usually weak)!
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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Metals are brilliant conductors of heat and electricity thanks to those free-moving delocalised electrons. They also have high melting points and stay solid at room temperature because of strong electrostatic attractions.
Most pure metals are malleable (you can hammer them into shapes) because the layers of atoms can slide over each other. Alloys are different though - mixing different sized atoms distorts the layers, making them much harder.
Fullerenes are fascinating carbon molecules that form hollow spheres or tubes. These structures, made from hexagonal rings of carbon atoms, are used in everything from electronics to drug delivery systems because of their unique properties.
Cool fact: Fullerenes can trap other molecules inside their hollow structure, making them perfect for targeted drug delivery!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
1
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
App Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Sociology